A wonderful 2010 documentary from BBC Four, covering the late ’70s synthesizer bands. Interviews with the (original) Human League, Depeche Mode, Orchestral Manoeuvres, Vince Clarke, Gary Numan, New Order and the Pet Shop Boys.
YouTube copies keep getting takedowns from Warner Music, so if all else fails there’s this copy of a broadcast with Spanish subtitles.
If you’re in the UK, a 60-minute compilation Synth Britannia at the BBC is on iPlayer for the next twenty-three days. Switch on the subtitles for the lyrics.